Corner seat frame



FIG. 1 is a perspective view of a corner seat frame showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevational view thereof, the front being a mirror image thereof; and

FIG. 4 is a left side elevational view thereof, the rear being a mirror image thereof. 

The ornamental design for a corner seat frame, substantially as shown and described. 